Battlefield 3

Load up one of the four new maps using the game mode CTF. Each base has a few motorcycles scattered around, so it won't be a problem finding one to ride. You won't need to have a second player driving you nor do you need to be moving at the time of the kill so this achievement is not as tricky as it sounds.

There are a few different tactics which I recommend. The first is to camp your own flag. Make sure you switch positions on the bike to the back seat and equip the gun you're most proficient with and wait. It shouldn't be long before any enemy coming to collect your flag falls into your line of sight. Execute and achievement unlocked.

Another sound method is equip your engineer class with a Javelin and find some high ground. Target one of the enemies motorcycles driving around once you have a lock, fire. The bikes are weak and you just earned yourself an easy kill. Remember to use caution as you don't want to fall victim to your own tactic.

Last there is nothing like riding shotgun with a shotgun. If you have a buddy who is capable, let him drive while you sit on the back with some slugs. It doesn’t take long to find an enemy on foot and if you can get close enough they will drop in one shot.

An easy way to get this is to lay tank mines in high traffic areas of the map, once done, hop on a bike and wait for a kill.

It counts if your on the passenger position or driving. C4 and claymores also work, just make sure your on the bike when it gets a kill.

Alot easier than getting a gun kill, good luck.

Battlefield 3 its No Sidecar Achievement

Battlefield 3 Its No Sidecar Achievement
This video will show you how to do the Battlefield 3 Its No Sidecar Achievement
Kill someone from the passenger position on a motorcycle.

There is more dramatic ways to do this but this way works